Skip to main content

Full text of "Arduino"

See other formats

Instant AC Power Filtering 


Make Projects 

build, hack, tweak, share, discover,' 

Instant AC Power Filtering 

Written By: Jeff Faust 


Electrolytic capacitor (1) 


You've been working hard at your Ardui no-based servo project, and so far it's working great. 
Time to untether it from your computer and let it run on its own, right? It works fine on USB 
power. It works fine on a 9-volt battery (while it lasts). You plug it into an adapter 
and... twitch... twitch... twitch. Suddenly it's not functioning anymore. Damn! 

If the adapter voltage is within range, and current supply is adequate, your problem is likely 
filtering: the adapter is not eliminating the ripple voltage, and that's interfering with the 
Arduino's ability to control the servo. Here's a quick way to clean up your power and get your 
project moving again. 

© Make Projects Page 1 of 2 

Instant AC Power Filtering 

• Carefully bend the capacitor's 
leads as shown, so that they can 
be inserted into the header without 
fouling other wires or components. 

• The positive lead is inserted into 
V in ; the negative goes to GND. I'm 

using a Seeed Protoshield for my 
project. The capacitor may be 
attached to the appropriate pins of 
the shield, or to the Arduino itself. 

• Inspect your connections one more 
time to make sure that nothing will 
short out, then attach your adapter. 
Your project should work fine. 

• Note that I'm using a 2200uF 
capacitor here-that's probably 
oversized, but it's getting the job 

This document was last generated on 201 2-1 2-04 03:25:43 AM. 

© Make Projects 

Page 2 of 2